The present invention relates to a device, respectively, a method for wet treatment of substrates in a container that contains a treatment fluid, whereby the substrates, on a substrate carrier, are introduced into the container.
From EP-A-0 385 536 a method for drying of semi-conductor wafers after treatment in a liquid is known. Furthermore, from this printed document it is known to treat wafers positioned in a cassette in a liquid bath whereby the wafers during treatment rest on supports within the cassette. After treatment, an auxiliary cassette is moved directly above the cassette with the wafers positioned within in the liquid. A blade-like lifting device lifts the wafers from the liquid whereby the wafers are dried. During lifting, the wafers are guided in lateral guides of the cassette and, after removal from the liquid, in lateral guides of the auxiliary cassette. When the wafers are completely lifted out of the liquid, the cassette is also lifted from the liquid and dried. The auxiliary cassette is moved in the upward direction so that the wafers again rest on the supports of the cassette outside of the liquid.
In such an arrangement there is however the problem that the wafers in the cassette within the container are not sufficiently aligned, respectively centered, so that they cannot be lifted without risk of damage into external guides, for example, in the aforementioned auxiliary cassette above the liquid. Even for a very minimal deviation from a vertical position, the wafers cannot safely be introduced into the external guides so that the risk of breakage is great. The transport cassettes are exposed to great temperature fluctuations, for example, during the treatment processes temperatures of up to 170.degree. C. may occur, so that tolerance values cannot be maintained, respectively, the cassette may be deformed.
It is therefore an object of the present invention to provide a device for wet treatment with which the substrates in the treatment container and during removal from the treatment container can be aligned and centered as precisely as possible.
A further object of the invention is to provide a carrier for the substrates whose position in the treatment container is always defined, despite occurring temperature fluctuations during treatment. This is also intended for improving the alignment and centering of the substrates.